[HN Gopher] How Excessive Red Meat Consumption Increases Colorec...
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       How Excessive Red Meat Consumption Increases Colorectal Cancer Risk
        
       Author : gnabgib
       Score  : 38 points
       Date   : 2024-10-25 16:57 UTC (6 hours ago)
        
 (HTM) web link (www.nccs.com.sg)
 (TXT) w3m dump (www.nccs.com.sg)
        
       | bell-cot wrote:
       | Summary: In the lab, using selected "standard lines" of cancer
       | cells, it looked fairly plausible that iron encourages the growth
       | of colorectal cancer cells.
       | 
       | Eating "excessive" red meat seems very likely cause high iron
       | concentrations in your lower intestines. Beyond that - YMMV.
        
         | cynicalpeace wrote:
         | So it's a junk headline? Also, telomerase activation is heavily
         | correlated with longevity and less risk of disease.
        
           | riku_iki wrote:
           | Per dietaryguidelines.gov cereal contains 8 times more iron
           | per calory than beef: https://www.dietaryguidelines.gov/resou
           | rces/2020-2025-dietar...
        
             | cynicalpeace wrote:
             | So the answer is yes, lol
        
             | Bluescreenbuddy wrote:
             | Is this why millennials and early genx are seeing higher
             | rates
        
         | photonthug wrote:
         | > Beyond that - YMMV.
         | 
         | Looking at Inuit and Mongolian populations for stuff like this
         | would likely be a good approach to actually learn stuff. Almost
         | a strictly meat diet, but without all the confounding variables
         | of sedentary office workers, industrial chemicals, and highly
         | processed foods with tons of sugar.
        
           | stackghost wrote:
           | There's more to it than diet. Genetics also plays a large
           | role. I'd be leery of generalizing dietary advice across
           | ethnicities.
        
             | inglor_cz wrote:
             | ... and microbiota, too. Colorectal cancer is located at
             | the end of a very densely "populated" tube.
             | 
             | In all likelihood, Inuit microbiota is very far from
             | Western one, at least as long as they don't adapt Western
             | diet.
        
         | jollyllama wrote:
         | I wonder if tea, coffee, wine, phytate containing foods (beans,
         | nuts) and calcium rich foods (dairy, etc) would counter the
         | risk by blocking iron absorption.
        
           | fyt2024 wrote:
           | Just getting celiac disease would counter iron intake :-)
        
         | tcdent wrote:
         | The correlation with Iron makes me wonder if the polymerization
         | of cooking oils is related.
         | 
         | https://www.lodgecastiron.com/cleaning-and-care/cast-iron/sc...
        
         | Findecanor wrote:
         | I have heard of there having been earlier studies that have
         | linked iron intake with colon cancer growth, and I have
         | personal reason to believe them.
         | 
         | I have Lynch syndrome: a hereditary cell mutation which
         | increases risk of colon cancer. Patients like me get a
         | colonoscopy every eighteen months or so only to remove polyps.
         | For a decade I had not had a single polyp to remove.
         | 
         | Then in 2022, I got another cancer which gave me blood
         | deficiency (low hemoglobin levels), and just to keep myself
         | alive I took strong iron supplements for months. It did of
         | course also stress my immune system. I got colon cancer in
         | record time, which surprised also my doctors. It grew from no
         | visible polyp (my last colonoscopy) to two inches in nine
         | months, and in-between that I had an X-ray that also showed
         | nothing (but which can't detect tumors small enough).
        
       | smm11 wrote:
       | Everything in excess might be a problem. I guess the Standard
       | American Diet is better, right?
        
       | henning wrote:
       | OK. How much red meat do you need to eat to have the excessive
       | high iron levels likely to trigger the behavior under
       | consideration in the study? How much higher is the risk?
       | 
       | Also, spinach has iron. So excessive spinach consumption at
       | levels that most people couldn't tolerate could also increase
       | colorectal cancer risk? Or no?
        
         | ygouzerh wrote:
         | That's a good question, spinach have the same type of iron than
         | in red meat, iron-(Fe3+), so it seems that it could a culprit
         | as well.
         | 
         | It looks like however the absorption of iron in red meat is
         | quite high (15%-35%) compared to spinach (2-5%), so maybe not
         | enough to really be a risk factor.
        
         | stackghost wrote:
         | Vegans, especially vegan women of menstruating age, are well
         | known to be almost universally iron-deficient, because our
         | bodies absorb iron from meats much more readily than other
         | (such as vegan) sources.
         | 
         | Interestingly, Vitamin C increases the rate at which you can
         | get iron from greens such as spinach. So maybe a glass or
         | orange juice and a bowl of salad a day keeps the doctor away.
        
           | david-gpu wrote:
           | If you want vitamin C without the sugar load of drinking
           | orange juice, you may be interested to learn that bell
           | peppers have a _much_ higher content of vitamin C than
           | oranges, either per gram or per calorie.
           | 
           | Edit: Let me offer some USDA data points for those who are
           | curious, but not curious enough to bother Googling for
           | themselves.
           | 
           | Red Bell Peppers: https://fdc.nal.usda.gov/fdc-
           | app.html#/food-details/170108/n...
           | 
           | Green Bell Peppers: https://fdc.nal.usda.gov/fdc-
           | app.html#/food-details/2258588/...
           | 
           | Oranges: https://fdc.nal.usda.gov/fdc-app.html#/food-
           | details/746771/n...
        
             | selimthegrim wrote:
             | Even green ones?
        
           | DiscourseFan wrote:
           | Yeah but Vegans consume a lot of vitamin C so that makes a
           | lot of sense.
           | 
           | Also explains why I crave red meat and vitamin C after a
           | workout. Can't get enough of the stuff.
        
             | okdood64 wrote:
             | Interesting; I have never craved vegetables or fruits after
             | a strength training workout. Only anything high in protein.
             | Eggs, red meat, chicken, whatever.
        
           | aziaziazi wrote:
           | False! probably? :)
           | 
           | Vegetarian resource group 2018
           | https://www.vrg.org/nutrition/iron.php
           | 
           | > Some might expect that [...] vegans might be prone to
           | developing iron deficiency anemia. However, surveys of vegans
           | have found that iron deficiency anemia is no more common
           | among vegetarians than among the general population although
           | vegans tend to have lower iron stores.
           | 
           | > In fact, if the amount of iron in these foods is expressed
           | as milligrams of iron per 100 calories, many foods eaten by
           | vegans are superior to animal-derived foods.[...] you would
           | have to eat more than 1700 calories of sirloin steak to get
           | the same amount of iron as found in 100 calories of spinach.
           | 
           | > Another reason for the satisfactory iron status of vegans
           | is that vegan diets are high in vitamin C
           | 
           | 2021 Norway health institute
           | https://pubmed.ncbi.nlm.nih.gov/33803700/
           | 
           | > In conclusion, although the participants were eating a
           | plant-based diet, the majority had sufficient iron status
           | 
           | Nutrients 2021 https://www.mdpi.com/2072-6643/13/9/2964
           | 
           | > We did not find differences in the prevalence of iron
           | deficiency between vegetarians and omnivores among men and
           | women who do not menstruate. Among women who menstruate,
           | vegetarians had a higher prevalence of iron deficiency than
           | omnivores did.
           | 
           | In this last one they'll mixed non-omnivorous together. Not
           | sure why, and how to calculate it.
        
         | pessimizer wrote:
         | Spinach doesn't have a lot of iron. The reputation is due to a
         | late-19th century study that was mistaken, and found that
         | spinach had 10x the iron that it actually does.
         | 
         | https://historiesofecology.blogspot.com/2015/08/on-spinach-i...
        
           | selimthegrim wrote:
           | "We regret to inform you that the people who were sacked have
           | just been sacked themselves"
           | 
           | https://www5.in.tum.de/~huckle/Sutton_Spinach_Iron_and_Popey.
           | ..
        
       | m0llusk wrote:
       | Iron supplements are often used, so it would be interesting to
       | know if they also might be significant risk factors.
        
       | fyt2024 wrote:
       | I remember a paper long time ago that claimed that one reason why
       | women have higher life spans than men is lower iron content in
       | their blood due to menstruation.
        
         | homarano wrote:
         | Women have a consistently lower mortality rate than men at all
         | ages 20-80 with no notable change around menopause.
         | 
         | https://www.researchgate.net/figure/Mortality-rate-for-men-a...
        
           | DiscourseFan wrote:
           | Men tend to be in higher risk situations more often than
           | women.
        
             | Beijinger wrote:
             | "..that one reason why.."
             | 
             | Reading competence
        
               | averageRoyalty wrote:
               | Please refrain from personal attacks.
        
         | QuercusMax wrote:
         | Here's an interesting article that talks about sexual
         | differences in life span, which seems to be correlated with the
         | size of the sex chromosome:
         | https://www.science.org/content/article/secret-long-life-mat...
         | 
         | Basically, for whatever reason, a larger sex chromosome (X is
         | much bigger than Y) confers a better chance of survival.
        
           | tuatoru wrote:
           | I thought it was because females have two copies of the X, so
           | defects in a region of one copy can be compensated for by the
           | other. RAID-1 ftw.
        
           | DiscourseFan wrote:
           | >This unevenness hints that factors other than the presence
           | of certain sex chromosomes might also strongly influence
           | longevity, the team says. One of these factors could be
           | sexual selection. Exaggerated physical traits and elaborate
           | behaviors make males of some species more attractive to
           | females but require large amounts of energy and take a toll
           | on overall health.
           | 
           | Perhaps the riskiness of male behavior in humans is built in
           | at the chromosonal level...
        
       | samatman wrote:
       | Headline stripped of bullshit: "Fe(3+) reactivates telomerase of
       | _in vitro_ colorectal cancer cells ".
        
         | eshack94 wrote:
         | It took me way too long to find that (I didn't notice your
         | comment til after).
         | 
         |  _Sigh_ at the clickbait headlines.
        
       | naming_the_user wrote:
       | It pays to be careful with studies like this because even if the
       | statement given is proven to be true, that does not logically
       | imply that it is optimal to reduce red meat consumption.
       | 
       | As a thought experiment (I'm completely making up these claims,
       | but they do at least seem plausible), imagine a world in which
       | regular coffee consumption resulted in some small increase in
       | cancer risk, but then also regular coffee consumption was
       | correlated with say, academic success, success at work, had some
       | appetite suppressing effects, etc.
       | 
       | If the latter outweighs the former then the cancer risk is
       | probably worth it even just longevity wise. Like how we know that
       | going out in the sun increases cancer risk but also is just,
       | well, good for us, to a degree.
       | 
       | But of course the media will just run with a headline, which is
       | why it sometimes feels as if the science is constantly
       | "changing".
        
         | aziaziazi wrote:
         | Average hn reader needs more sun exposure than he does because
         | the vitD boost will probably worth the cancer risk.
         | 
         | With red meat the known benefits peaks (way) lower than average
         | consumption. I'm not an expert but that looks to be shown more
         | than the opposite. On a personal anecdote my doctor tells last
         | week optimum is at 1meal/2weeks. He's maybe not aware of
         | breaking discoveries but this looks to be in range with what's
         | discussed here and there.
         | 
         | I like critical thinking nevertheless and it would be
         | interesting to learn more.
        
           | naming_the_user wrote:
           | Right. The question remains though about what we mean by
           | "known benefits".
           | 
           | I chose caffeine as an example because I think that it's
           | completely nontrivial to calculate. The physical pathways of
           | things like "well this makes that molecule do this and have
           | some x% chance to mutate and so on and so you get cancer", or
           | the statistical output of "well people in the coffee cohort
           | have % higher rates of this cancer" are much easier to
           | accurately study than things like "if you drink coffee you
           | are 3% more likely to get into law school and therefore
           | become significantly wealthier and probably live a
           | longer/healthier life and we can measure that impact
           | precisely".
           | 
           | It's also not at all obvious that lifespan above all else is
           | the thing to maximise. e.g. maybe red meat reduces lifespan
           | but makes your 20s-60s more fun because you're likely to be
           | more muscular or whatever.
           | 
           | My personal feeling is that aside from really really bad
           | things like smoking, heavy alcohol use, heroin etc the error
           | bars are too large to make decisions purely on long-term
           | health impact alone.
        
             | xcrunner529 wrote:
             | Why are you so eager to fantasize about some "other
             | benefit" with no evidence whatsoever of it, while evidence
             | is presented on the harmful effects in many studies at this
             | point. Would you think the same way about "poisons" or
             | plastic contamination? Pollution?
             | 
             | Correlation != causation and all of that, but as the US has
             | increased meat consumption and processed foods colon cancer
             | has been on the rise, including younger and younger adults.
        
               | throw_pm23 wrote:
               | Why would you think the same way about the benefits of
               | plastic contamination as the benefits of red meat? One
               | was consumed for millions of the years, the other has
               | been around for decades.
        
               | naming_the_user wrote:
               | I think you're comparing two things here.
               | 
               | Eating red meat is overall a beneficial activity. It
               | might be suboptimal / marginally less healthy compared to
               | say, eating chicken or tofu.
               | 
               | Consuming plastic particulates, pollution, poisons etc
               | are completely undesirable.
               | 
               | A better example might be something like drinking water
               | out of a plastic bottle. Maybe the plastics leach into
               | the water. But maybe the health benefit of always having
               | a bottle of water with you is worth it.
        
           | fakedang wrote:
           | I wrote this in another comment earlier, but red meat is the
           | most energy-efficient food source available for consumption
           | in digestive terms, simply because our bodies were designed
           | to process large amounts of protein rapidly - compared to
           | plant matter that needs to be broken down multiple times.
           | There's a reason herbivores have 4 stomachs. Human bodies
           | basically evolved as Apex predators and a meat diet helped
           | that, as well as was responsible for it. Meat, berries and
           | tubers for hunter-gatherers to put it succinctly.
           | 
           | We only adopted carbs because back in the day, cereals were
           | the most efficient way to feed a large population (compared
           | to say large-scale veggie cultivation) for an active societal
           | workforce. But with us slowly and inevitably turning into
           | lumbering sedentary creatures, it makes no sense to continue
           | eating as many carbs as we are culturally accustomed to,
           | instead resorting to meats and veggies to adequately cover up
           | that deficit. Unfortunately, you need a ton of veggies to
           | make up that deficit, but you can make do with a much smaller
           | sized portion of meat than you're usually accustomed to (as
           | we see with East Asian diets).
        
       | throw_pm23 wrote:
       | Is it the meat or the sodium nitrite used to cure it?
       | 
       | https://en.wikipedia.org/wiki/Sodium_nitrite#Cancer
        
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